The present invention relates to a liquid ejecting head unit provided with a liquid ejecting head capable of effecting printing on a print medium by ejecting droplets through ejection outlets, a carriage for carrying the liquid ejecting head unit, and a printing apparatus equipped with them. The present invention also relates to a positioning method of the liquid ejecting head unit, and an inserting method therefor.
In a conventional printing apparatus, the use is made with a liquid ejecting head unit which includes a liquid ejecting head for effecting print on a print medium by ejecting the ink through the ejection outlets, and an ink container accommodating the ink to be supplied to the liquid ejection printing head, which may be integral or separate. The liquid ejection printing apparatus is provided with a carriage reciprocable in a substantially perpendicular to the feeding direction of the print medium, and the liquid ejecting head unit is barred on such a carriage.
As the liquid ejecting head, known ones include a liquid ejecting head which ejects fine droplets using thermal energy generated by electrothermal transducers or the like, and a liquid ejecting head which ejects the droplets deflected by a pair of electrodes. Among them, an ink jet printing head which ejects the ink droplets using the thermal energy has advantages in that liquid ejection portions (ejection outlets) for forming the printing droplet can be arranged at high density, and therefore, high resolution print is possible and in that total size of the printer can be reduced, and such an ink jet printing head has been put into practice.
The ink jet printing head is provided with a plurality of ejection outlet, a plurality of liquid flow paths in fluid communication with the respective ejection outlet, and a plurality of energy conversion elements such as electrothermal transducer elements disposed in the respective liquid flow paths, wherein ejection energy (the thermal energy effective to create film boiling in the liquid, for example) is applied to the liquid by the energy conversion element, by which the liquid droplet is ejected to effect printing. Referring to FIG. 73, the description will be made as to a general structure of the ink jet printing head.
As shown in FIG. 73, the ink jet printing head comprises an element substrate 1001 provided with a heat generating element 1001a (energy producing member) for ejecting the ink, a top plate 1002 connected to the element substrate 1001, and an orifice plate 1010 connected to the element substrate 1001 handed to the front end surface of the top plate 1002.
The element substrate 1001 is fixed to the supporting member 1004 of aluminum or the like by die bonding. To the supporting member 1004, an element substrate 1001 and a printed wiring substrate 1003 for effecting electric contact with the main assembly of the printing apparatus are bonded, and the printed wiring substrate 1003 and the element substrate 1001 are electrically connected by wire bonding. Although not shown in the Figure, the printed wiring substrate 1003 is equipped with a contact pad for contact with the main assembly of the printing apparatus. On the element substrate 1001, there are provided a shift register and a wiring pattern in addition to the heat generating element 1001a s. The shift register and the wiring pattern may be built in the element substrate 1001 together with the heat generating elements 1001a through silicon formation technique.
The top plate 1002 is made of a resin material integrally having recesses which constitute the ink flow paths 1002a and a recess which constitutes the ink liquid chamber 1002b through an injection molding or the like, or made of silicon material through an anisotropic etching process or the like. The top plate 1002 is fixed to the element substrate 1001 by urging means (unshown) such as a spring or by connecting means (unshown) such as adhesive material or the like, thereby providing a plurality of ink flow paths 1002a corresponding to the respective heat generating elements 1001a and providing the ink liquid chamber 1002b for supplying the liquid to the liquid flow path 7s. 
The orifice plate 1010 has group of fine ink ejection outlets 1010a for ejecting the ink, and the outlets are formed through a laser machining, electro-forming, press work injection molding or another ultra-fine processing. The group of ejection outlets 1010a is one of important factors influential to the ejection performance of the liquid ejection printing head. The orifice plate 1010 may be formed integrally with the top plate 1002 in one case, and is formed by connecting a separate top plate 1002 thereto. In the latter case, the ejection outlets 1010a of the orifice plate 1010 are aligned with and connected to the ink flow paths 1002a provided by the press-contact between the element substrate 1001 and the top plate 1002, and this is advantageous in that material of the orifice plate 1010 which requires durability can be relatively freely selected. On the other hand, in the former case, the ejection outlets 1010a and the ink flow paths 1002a can be formed with the fluid communication accomplished therebetween, and therefore, the ink flow paths 1002a can be provided by simple mechanical press-contact between the top plate 1002 and the element substrate 1001 so that productivity is good.
The ink jet printing apparatus using the ink jet printing head described above is usable with a word processor, a color printer connected with a personal computer, a facsimile machine, a copying machine or the like.
FIG. 74 is a perspective view of a conventional liquid ejecting head unit (ink jet print cartridge). As shown in the Figure, the main assembly 1130 of the ink jet print cartridge comprises an ink jet printing head H at a predetermined position, and a first common liquid chamber 1120 is disposed adjacent the ink jet printing head H. The first common liquid chamber 1120 and the ink jet printing head H are supported by supporting member 1121, 1122 s. In the main assembly 1130 of the ink jet print cartridge covered with a cap member 1131, there is provided a container (unshown) containing printing liquid such as ink, and the printing liquid is properly supplied from the container to the first common liquid chamber 1120.
The ink jet printing head H may be an integral type in which one printing head is provided with ink ejection portions for respective colors, for example, black, yellow, magenta and cyan. With such a type, the number of ejection outlets per color is small, but the head is less expensive. However, the integral type head is not advantageous for the high speed printing.
In another type, which may be costly, a plurality of ink jet print cartridges are juxtaposed, and the printing heads for the respective colors are independently provided, in which the number of ejection outlets can be made larger. In another type, the independent plurality of ink ejection portions are mounted on a single base. With this type, the printing heads are disposed on the base with high precision on the basis of predicted positional deviations among ink droplets injected from the ejection outlets in the orifice plate for the respective colors. Additionally, since the printing heads are integrally mounted on the base, the misregistration of the colors is small, and the exchange of the head is easy.
FIG. 75 is a perspective view of an ink jet recording head assembly disclosed in Japanese Laid-open Patent Application Hei 9-289971.
The conventional ink jet recording head assembly 1306 shown in the Figure comprises a base 1301 having a plurality of ink ejection portion with ink ejection outlet, and a printed board 1302 having a ROM1304 storing positional data set for the respective ink ejection portions on the basis of actually measured positional deviations among the ink droplets ejected from the ink ejection outlets of the ink ejection portions, and storing property data peculiar to the ink ejection portion and data for correcting the property.
The ink jet recording head assembly is provided with an ink supply port 1303 receiving a supply of the ink from an unshown ink container or the like. The printed board 1302 is equipped with a contacting electrode 1305 for electrically connecting the ink jet recording head assembly to a controller of the main assembly of the recording device.
When the printing operation is carried out, the controller in the main assembly of the recording device effects correction process for the generation timing and the pulse of the driving signal for driving the producing member for generating the ejection energy to eject the ink on the basis of the data stored in the ROM1304. By doing so, occurrences of print defect such as misregistration of print can be prevented.
Recently, the demand is directed to high speed and high image quality full-color print, and therefore, the improvement in the printing speed, the resolution and a tone gradient is further desired. In other to accomplish a print having a quality equivalent to a photograph, a proposal has been made as to a use of six colors or seven colors ink container containing the above described four color inks (black, yellow, magenta and cyan inks) plus inks of the same colors but having different densities.
In order to accomplish the high speed, high image quality ink jet printing apparatus, it is desirable to use a type having a plurality of ink jet print cartridges, or a set type or a combination thereof.
In another accomplish a high image quality color image without color non-uniformity or misregistration, it is desired that position of the ink droplet deposited on the print medium from the printing head (deposition position) is correct. Particularly, a relative inclination of the printing head in the direction of the ejection outlet arrangement is most influential to the print quality, and it is desirable that error in the relative inclination of the printing head in the direction of the ejection outlet arrangement is minimum. As a measure for reducing the relative inclination in this direction, it is known that abutting portion for abutment to a predetermined position of the carriage is provided in the ink jet print cartridge so that ejection outlets of the printing head are correctly positioned.
FIG. 76 shows a conventional example in which a plurality of liquid ejecting units (ink jet print cartridges) are juxtaposed and fixed on the carriage.
In this Figure, designated by 418 shows one ink jet print cartridge. In a frame 482 which functions as a casing of the ink jet print cartridge 481, there is provided an ink storing chamber for containing the ink. Designated by a reference numeral 483 is a face in which ejection outlets (unshown) are provided, and 484 is a contact pad to be electrically connected with a contact provided in the carriage on which the cartridge is mounted, and 485 is an ink supplying portion for supplying the ink into an ink storing chamber in the frame 482.
The frame 482 is provided with projections 482a and 482b, which are abutted to predetermined positions of the carriage so that ink jet print cartridge 481 is correctly positioned. The carriage is provided with pressing means (unshown) at a central portion of the projections 482a and 482b, which is defective to abut the projections 482a, 482b to the carriage. The pressing means for fixing the ink jet print cartridge 481 includes a means for urging the cartridge downwardly and a means for urging the contact pad and a carriage contact (unshown) to each other.
As described hereinbefore, the recent demand is directed to high speed and high image quality full-color print, and therefore, the improvement in the printing speed, the resolution and a tone gradient is further desired. Therefore, the position of deposition of the ink droplet on the print medium is decided to be more correct.
Even if the conventional positioning method in which the liquid electing head unit is adopted to the predetermined position of the carriage, is not enough to properly adjust the relative inclination in the direction of the ejection outlet arrangement in the printing head with a sufficient precision.
It is considered that liquid electing head unit is supported for rotation about a predetermined fulcrum, and a cam mechanism is provided at a position remote from the fulcrum to adjust the inclination.
As described in the foregoing, in the liquid ejecting head unit, the relative inclination into direction of the ejection outlet arrangement of the liquid ejecting head is significantly influence to the print quality, it is desirable that relative inclination in the direction of the ejection outlet arrangement is minimized. Heretofore, in order to solve this problem, an abutting portion of the liquid ejecting head unit at the predetermined position is abutted to a predetermined position of the carriage. However, with such a structure, a high precision connecting portion is required between the liquid ejecting head unit and the carriage, and therefore, the cost is high, and the yield is low.
Additionally, in the conventional example, the casing (frame) of the liquid ejecting head unit is easily be formed (support at each of the opposite ends), and therefore, the positional accuracy tends to be low, and the mounting-and-demounting of the liquid ejecting head unit is not uniform.
Furthermore, in the conventional example, the liquid ejecting head unit is relatively easily inclined in any directions, and therefore, the relative inclination of the liquid ejecting head unit in the ejection outlet arranging direction may become large after it is mounted on the carriage. However, in the conventional example, once the relative inclination in the ejection outlet arranging direction occurs, the inclination cannot be corrected, and therefore, the printing operation may be carried out with the large relative inclination in the ejection outlet arranging direction.
Accordingly, it is a principal object of the present invention to provide a printing apparatus and a liquid ejecting head unit in which the user can easily mount a liquid ejecting head unit on a carriage provided with an adjusting mechanism portion with which an angular position is adjustable.
It is another object of the present invention to provide a carriage and a liquid ejecting head unit wherein the relative inclination of the liquid ejecting head in the direction of the ejection outlet arrangement, so that print quality is stabilized.
It is a further object of the present invention to provide a printing apparatus provided with such a carriage and such a liquid ejecting head unit.
It is a further object of the present invention to provide a liquid ejecting head unit positioning method usable with such a printing apparatus.
According to an aspect of the present invention, there is provided a printing apparatus comprising: a liquid ejecting head unit for effect printing on a print medium by ejecting droplets from ejection outlets; a carriage for detachably mounting the liquid ejecting head unit, the carriage being provided with an angular position adjusting mechanism portion for rotatably positioning the liquid ejecting head unit; a liquid ejecting head unit including a pin functioning as a fulcrum for the rotation and a projection for guiding the carriage to a predetermined position; wherein the carriage is provided with a hole for supporting the liquid ejecting head unit by insertion of the pin thereinto, and a guide portion on which the projection is slidable.
According to another aspect of the present invention, there is provided a printing apparatus comprising; a liquid ejecting head unit for effect printing on a print medium by ejecting droplets from ejection outlets; a carriage for detachably mounting the liquid ejecting head unit, the carriage being provided with an angular position adjusting mechanism portion for rotatably positioning the liquid ejecting head unit; a liquid ejecting head unit including a hole functioning as a fulcrum for the rotation and a projection for guiding the carriage to a predetermined position; wherein the carriage is provided with a pin for supporting the liquid ejecting head unit by insertion thereof into the hole, and a guide portion on which the projection is slidable.
According to a further aspect of the present invention, there is provided a printing apparatus comprising: a liquid ejecting head unit for effect printing on a print medium by ejecting droplets from ejection outlets; a carriage for detachably mounting the liquid ejecting head unit, the carriage being provided with an angular position adjusting mechanism portion for rotatably positioning the liquid ejecting head unit; wherein the liquid ejecting head unit is provided with a projection for guiding the liquid ejecting head unit to a predetermined portion of the angular position adjusting mechanism portion; wherein the carriage is provided with a guide portion on which the projection is slidable.
According to a further aspect of the present invention, there is provided the liquid ejecting head unit is limited by the projection so as not to be disengaged from a predetermined position of the angular position adjusting mechanism portion when the liquid ejecting head unit is removed from the carriage.
According to a further aspect of the present invention, there is provided a method inserting a liquid ejecting head, comprising: a step of providing a liquid ejecting head unit for effecting printing on a print medium by ejecting droplets from ejection outlets with a pin functioning as a fulcrum for rotation of the liquid ejecting head unit and with a projection for guiding the pin to a predetermined position; a step of providing a carriage which rotatably mounts the liquid ejecting head unit and which is provided with an angular position adjusting mechanism portion for rotatably positions the liquid ejecting head unit, with a hole for supporting the liquid ejecting head unit by supporting the pin and a guide portion for guiding the projection to a predetermined position; a step of inserting the liquid ejecting head unit to a predetermined position in the carriage while abutting the projection to and sliding it on the guide portion so as the insert the pin into the hole.
According to a further aspect of the present invention, there is provided a method inserting a liquid ejecting head, comprising; a step of providing a liquid ejecting head unit for effecting printing on a print medium by ejecting droplets from ejection outlets with a hole functioning as a fulcrum for rotation of the liquid ejecting head unit and with a projection for guiding the pin to a predetermined position; a step of providing a carriage which rotatably mounts the liquid ejecting head unit and which is provided with an angular position adjusting mechanism portion for rotatably positions the liquid ejecting head unit, with pin for supporting the liquid ejecting head unit by being inserted into the hole and a guide portion for guiding the projection to a predetermined position; a step of inserting the liquid ejecting head unit to a predetermined position in the carriage while abutting the projection to and sliding it on the guide portion so as the insert the pin into the hole.
According to a further aspect of the present invention, there is provided a method of inserting a liquid ejecting head, comprising: a step of providing a liquid ejecting head unit for effecting printing on a print medium by ejecting droplets from ejection outlets with a projection for guiding the liquid ejecting head unit to a predetermined position; a step of providing a carriage which rotatably mounts the liquid ejecting head unit and which is provided with an angular position adjusting mechanism portion for rotatably positions the liquid ejecting head unit, with a guide portion for guiding the projection to a predetermined position; a step of inserting the liquid ejecting head unit to a predetermined position of the angular position adjusting mechanism portion while abutting the projection to and sliding it on the guide portion so as the insert the pin into the hole.
With the above described printing apparatus or the liquid ejecting head unit insertion method, the projection is provided on the side surface of the liquid ejecting head unit come and the liquid ejecting head unit is inserted to the carriage while the projection slides on the guide portion of the carriage, so that liquid ejecting head unit is correctly led to the predetermined the position of the angular position adjusting mechanism portion provided in the carriage. Additionally, a pin functioning as a pivot of the rotational of the liquid ejecting head unit is correctly led to a hole for the pin.
According to an aspect of the present invention, there is provided a carriage for carrying a liquid ejecting head unit for effecting printing by ejecting droplets through a plurality of ejection outlets, comprising: means for supporting the liquid ejecting head unit for rotation about a predetermined portion; and means for adjusting an angular position of the liquid ejecting head unit supported by the supporting means.
According to another aspect of the present invention, there is provided a casing of the liquid ejecting head unit has a guide pin having a circular column configuration at a predetermined position of a bottom surface thereof, a first spherical projection on a side surface adjacent the guide pin, and a second projection on a side surface adjacent the side surface having the first projection, and wherein the carriage includes a first U-shape or V-shape receiving portion having a cylindrical inner surface for receiving an outer surface of the guide pin, a second U-shape or V-shaped receiving portion having a cylindrical inner surface for receiving the first projection, and a third receiving portion for receiving the second projection.
According to a further aspect of the present invention, there is provided a liquid ejecting head unit detachably mountable on a carriage, comprising: a liquid ejecting head for effecting printing on a print medium by ejecting droplet d from a plurality of ejection outlets; a casing for supporting the liquid ejecting head; wherein the casing including; a guide pin having a circular column configuration provided at a predetermined position of a bottom surface thereof; a spherical first projection provided on a side surface adjacent a side having the guide pin; and a second projection provided on a side surface adjacent the side surface having the first projection; and wherein the first and second projection and side guide pin are engageable with corresponding portions of the carriage.
According to a further aspect of the present invention, there is provided the guide pin and first projection constitutes a fulcrum for rotating the liquid ejecting head unit by engagement with corresponding portions of the carriage.
According to a further aspect of the present invention, there is provided a printing apparatus comprising: a liquid ejecting head unit for effecting printing by ejecting droplets from a plurality of ejection outlets; a carriage for detachably carrying the liquid ejecting head unit; wherein the liquid ejecting head unit is supported on the carriage for rotation about a predetermined portion of the liquid ejecting head unit, and an angular position of the liquid ejecting head unit supported thereon is adjustable.
According to a further aspect of the present invention, there is provided a casing of the liquid ejecting head unit has a guide pin having a circular column configuration at a predetermined position of a bottom surface thereof, a first spherical projection on a side surface adjacent the guide pin, and a second projection on a side surface adjacent the side surface having the first projection, and wherein the carriage includes a first U-shape or V-shape receiving portion having a cylindrical inner surface for receiving an outer surface of the guide pin, a second U-shape or V-shaped receiving portion having a cylindrical inner surface for receiving the first projection, and a third receiving portion for receiving the second projection.
According to a further aspect of the present invention, there is provided a positioning method for a liquid ejecting head unit in a printing apparatus, comprising: a step of contacting the first and second projections of the liquid ejecting head unit to the second and third receiving portions of the carriage while engaging the guide pin of the liquid ejecting head unit into the first receiving portion of the carriage; a step of engaging the guide pin and the first projection of the liquid ejecting head unit with the first and second receiving portions of the carriage; and a step of angle adjustment for adjusting an angular position of the liquid ejecting head unit.
According to the intention, the liquid ejecting head unit mounted on the carriage is rotated about the fulcrum at the predetermined position. Therefore, the relative inclination of the liquid ejecting head in the direction of the ejection outlet arrangement can be minimized by adjusting the angular position of the liquid ejecting head unit.
In addition, the control of the angular position of the liquid ejecting head unit can be carried out stepwisely at regular angles. In such a case, by counting to the number of the steps, the amount of the control can be known, and therefore, the angular position of the liquid ejecting head unit can be easily known. By selecting a fine angle for the step of the adjusted angle, the angle adjustment can be carried out with high precision.
Furthermore, the guide pin of the liquid ejecting head unit and first and second projections are engaged with first and third receiving portions of the carriage. By doing so, the liquid ejecting head unit is correctly mounted at the predetermined position of the carriage.